The membrane type (MT)-matrix metalloproteinases (MMPs) constitute a sub-group of membrane-anchored MMPs that are major mediators of pericellular proteolysis and physiological activators of pro-MMP-2. MT-MMPs activate the zymogenic form of MMP-2 (pro-MMP-2 or pro-gelatinase A). MMP-2, in turn, can activate pro-MMP-9. The MT-MMPs comprise six members of plasma-tethered MMPs, which include four type I transmembrane enzymes (MMP-14, -15, -16, and -24) and two glycosylphosphatidylinositol-anchored enzymes (MMP-17 and -25). In addition to being potent extracellular matrix (ECM)-degrading enzymes, the type I transmembrane MT-MMPs can also initiate a cascade of zymogen activation on the cell surface.
MMPs are extensively studied in cancer and inflammation, and are well-validated in preclinical studies. Existing treatments for cancer, such as chemotherapy and radiotherapy improve the quality of life with no life-prolonging benefits and have significant side effects. Other treatments, such as MMP inhibitors, are being developed and further refined, and may work most effectively in cancers where certain MMPs are being expressed.
Patient stratification allows healthcare providers to assess the risk/benefit ratio of a given treatment and to predict what patients may best respond to a certain course of treatment. In general, the higher the risk of a particular disease, the better the risk/benefit ratio. Relative risk reduction by a given treatment is often similar across subgroups divided by sex, age, blood pressure etc.; however, if the absolute risk is low it may not be worth taking a treatment with serious side effects. Patient stratification is also important in assessing the cost effectiveness of treatment for a given set of patients.